Temperature dependent structural evolution in liquid Ag₅₀Ga₅₀ alloy.

The temperature dependence of atomic structural evolution in the liquid Ag50Ga50 alloy has been studied by using in situ high energy X-ray diffraction (XRD) experiment combined with the first-principles molecular dynamics (FPMD) simulations. The experimental data show a reversible structural crossover at the temperature about 1050 K. Changes in both electrical resistivity and absolute thermoelectric power at about 1100 K strongly support the XRD results. Additionally, FPMD simulations reveal an abnormal temperature dependent behavior of partial coordination number and atomic diffusivity at about 1200 K, elucidating that the partition experimentally observed changes in structure and properties could be linked with the repartition between Ag and Ga atoms in the liquid at around 1050-1200 K. This finding will trigger more studies on the structural evolution of noble-polyvalent metals in particular and metallic liquids in general.